merge queue: embarking master (54490a3) and #311 together

[mergify]

🎉 This pull request has been checked successfully and will be merged soon. 🎉

Branch master (54490a3) and #311 are embarked together for merge.

This pull request has been created by Mergify to speculatively check the mergeability of #311.
You don't need to do anything. Mergify will close this pull request automatically when it is complete.

Required conditions of queue default for merge:

• check-success~=build \(2.13.\d+\)
• check-success~=build \(3.3.\d+\)

Required conditions to stay in the queue:

• author=scala-steward
  • Update scala-library to 2.12.21 #311
• base=master
  • Update scala-library to 2.12.21 #311
• check-success~=build \(2.13.\d+\)
  • Update scala-library to 2.12.21 #311
• check-success~=build \(3.3.\d+\)
  • Update scala-library to 2.12.21 #311

---
checking_base_sha: 54490a30075a4926c97a3bf9a6435665661bfa2b
previous_failed_batches: []
pull_requests:
  - number: 311
...